Summary about Disease
Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a genetic disorder that primarily affects red blood cells. It is caused by a lack or defect in the G6PD enzyme, which is crucial for protecting red blood cells from damage and premature destruction (hemolysis). This can lead to hemolytic anemia, where red blood cells are destroyed faster than they can be produced, resulting in a shortage of oxygen delivery throughout the body. The severity of G6PD deficiency varies, with some individuals experiencing no symptoms while others have severe, life-threatening hemolytic crises.
Symptoms
Many individuals with G6PD deficiency are asymptomatic until exposed to triggers. Symptoms, when they occur, usually develop rapidly and can include:
Jaundice: Yellowing of the skin and whites of the eyes.
Dark urine: Often described as tea-colored or cola-colored.
Fatigue: Feeling unusually tired or weak.
Dizziness: Feeling lightheaded or unsteady.
Shortness of breath: Difficulty breathing or feeling winded.
Rapid heart rate: An increased rate of heartbeat.
Splenomegaly: Enlargement of the spleen (felt as discomfort in the upper left abdomen).
Back or abdominal pain: Discomfort in the back or stomach area.
In severe cases: Acute kidney failure
Causes
G6PD deficiency is caused by a genetic mutation in the G6PD gene, which is located on the X chromosome. It is inherited in an X-linked recessive pattern. This means that males (who have one X and one Y chromosome) are more likely to be affected because they only need to inherit one copy of the mutated gene. Females (who have two X chromosomes) need to inherit two copies of the mutated gene to be affected, although they can be carriers if they have one copy. Triggers that can cause hemolysis in individuals with G6PD deficiency include:
Certain medications: Some antibiotics (e.g., sulfa drugs, nitrofurantoin), antimalarials (e.g., primaquine, chloroquine), and other drugs.
Certain foods: Fava beans (broad beans) are a well-known trigger, causing a reaction called favism.
Infections: Bacterial or viral infections can trigger hemolysis.
Stress: Severe stress.
Medicine Used
There is no specific medication to "cure" G6PD deficiency. Treatment focuses on managing the symptoms of hemolytic anemia and avoiding triggers.
Supportive care: In mild cases, simply removing the trigger and providing supportive care (e.g., rest, hydration) may be sufficient.
Blood transfusion: In severe cases of hemolytic anemia, a blood transfusion may be necessary to replenish red blood cells.
Oxygen therapy: If breathing is difficult due to anemia, supplemental oxygen may be administered.
Exchange transfusion: In severe cases, especially in newborns, exchange transfusion (replacing the infant's blood with donor blood) can be performed.
Folic acid: Folic acid supplementation may be recommended to support red blood cell production.
Is Communicable
No, G6PD deficiency is not communicable. It is a genetic disorder, meaning it is inherited from parents to their offspring and cannot be spread from person to person through contact, air, or other means.
Precautions
The most important precaution is to avoid known triggers of hemolytic anemia. This includes:
Medications: Always inform healthcare providers about G6PD deficiency before starting any new medication. Carry a list of medications to avoid.
Foods: Avoid fava beans and other foods known to trigger hemolysis.
Infections: Seek prompt medical attention for any infections.
Chemicals: Avoid exposure to naphthalene (mothballs), certain dyes, and other chemicals that may trigger hemolysis.
Vaccinations: Ensure all vaccinations are up-to-date to reduce the risk of infection.
Newborn Screening: Infants with a family history of G6PD deficiency should be screened at birth.
How long does an outbreak last?
The duration of a hemolytic crisis or "outbreak" in G6PD deficiency varies depending on the severity of the trigger and the individual's overall health. Mild episodes may resolve within a few days with removal of the trigger and supportive care. Severe episodes requiring hospitalization and blood transfusions can last for several weeks. Generally, once the trigger is removed and the body starts to produce new red blood cells, the symptoms gradually improve.
How is it diagnosed?
G6PD deficiency is diagnosed through blood tests that measure the level of G6PD enzyme activity in red blood cells.
G6PD enzyme assay: This is the primary diagnostic test. A low level of G6PD enzyme activity indicates a deficiency.
Complete blood count (CBC): This test measures the number of red blood cells, white blood cells, and platelets. It can reveal evidence of hemolytic anemia, such as a low red blood cell count (anemia), low hemoglobin, and elevated reticulocyte count (immature red blood cells).
Bilirubin level: Elevated bilirubin levels can indicate red blood cell breakdown.
Haptoglobin level: Haptoglobin binds to free hemoglobin released from damaged red blood cells. Low haptoglobin levels can suggest hemolysis.
Peripheral blood smear: Microscopic examination of a blood sample can reveal damaged red blood cells (e.g., bite cells, Heinz bodies).
Genetic testing: Genetic testing can confirm the presence of mutations in the G6PD gene.
Timeline of Symptoms
The timeline of symptoms after exposure to a trigger can vary, but generally follows this pattern:
Exposure to Trigger: Individual is exposed to a triggering medication, food, infection, or other agent.
Within 24-48 hours: Hemolysis (red blood cell destruction) begins.
1-3 days: Symptoms start to appear, including dark urine, jaundice, fatigue, and shortness of breath.
Days 3-7: Symptoms may worsen, potentially leading to severe anemia, rapid heart rate, and abdominal or back pain. Medical intervention, such as blood transfusions, may be necessary.
1-2 weeks (with treatment): Symptoms gradually improve as the trigger is removed and the body begins to replenish red blood cells.
Several weeks (severe cases): In severe cases, recovery can take several weeks, especially if kidney damage or other complications occur.
Important Considerations
Lifelong condition: G6PD deficiency is a lifelong condition.
Carrier status: Females who carry one copy of the mutated gene may have varying levels of G6PD enzyme activity. Some carriers may be asymptomatic, while others may experience mild to moderate symptoms, especially during times of stress or exposure to triggers.
Geographic distribution: G6PD deficiency is more common in certain parts of the world, including Africa, the Mediterranean, the Middle East, and Southeast Asia.
Newborn screening: Newborn screening programs can identify infants with G6PD deficiency, allowing for early intervention and prevention of hemolytic crises.
Education and awareness: Individuals with G6PD deficiency and their families should be educated about the condition, potential triggers, and emergency management.
Medical alert: Consider wearing a medical alert bracelet or carrying a card that identifies the individual as having G6PD deficiency.
Variations: There are many different variants of G6PD deficiency, some more severe than others.
Drug interactions: Always check with a doctor or pharmacist before taking any new medication to ensure it is safe for someone with G6PD deficiency.